WATFORD, ENGLAND – Wearing a baseball cap and sweatpants, Christian Ponder reached down to move a bag of footballs so Matt Cassel would have room to warm up before Friday’s practice at the Grove Hotel, about an hour outside of London.

What had been speculated since Wednesday had come to fruition. Ponder will have no more effect on Sunday’s game against the Steelers than one of the team’s ball boys. He will be inactive because of a fractured rib that’s too near his heart to risk having him get hit, Ponder and coach Leslie Frazier explained on Friday.

“It stinks,” Ponder said. “But I’ll be back for Carolina,” the Vikings’ next game after next week’s bye.

But will he?

Medically speaking, that shouldn’t be a problem. Ponder said doctors have told him with rest and treatment, he should be healed in about 10 days from when he suffered the injury, in last week’s loss to the Browns.

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Christian Ponder bided his time with quarterbacks coach Craig Johnson during practice Friday. Ponder did not participate in practice and won’t play Sunday against Pittsburgh in Wembley Stadium.

Football-wise? Well, that’s to be determined Sunday when Cassel makes his Vikings debut in a battle of two desperate 0-3 teams at Wembley Stadium.

“We really haven’t talked about that,” Ponder said when asked if he’s been told he’ll return as the starter once he’s healthy.

If Cassel jump-starts a 24th-ranked passing attack that has no touchdowns from a wide receiver, Frazier could go with the hot hand, as many teams, including last year’s NFC champion San Francisco 49ers, do.

Frazier’s concerns don’t extend beyond Sunday. He’s too busy trying to save a season and possibly his coaching career in Minnesota.

“I don’t foresee a quarterback controversy,” said Frazier, whose team faces the only defense in the league without a takeaway. “But we want [Cassel] to play lights-out, want him to have the best game of his NFL career on Sunday.”

Past struggles

If Cassel plays like he did in his final 17 starts in Kansas City — 5-12 with 28 turnovers — the Vikings probably will be 0-4 for the second time in three seasons. They also would have a full-blown mess on their hands because of Ponder’s struggles and a No. 3 quarterback, McLeod Bethel-Thompson, who is raw and has yet to play in a regular-season game.

“I hope [Cassel] plays well,” Ponder said. “This team needs him to play well. I think he will play well.”

Cassel said he’s not looking ahead because of the urgency of facing 0-4.

“For us,” he said, “it’s really a one-game season.”

Signing Cassel to replace Joe Webb in the offseason gave the Vikings a veteran with 62 starts (29-33) and someone who wouldn’t require a different game plan for everyone to learn. Those were two things several teammates pointed to after being told Friday morning that Ponder wouldn’t play.

Receiver Jarius Wright said Cassel is more assertive in the huddle, which comes with experience. From a passing standpoint, Wright said, “I really don’t see too much difference.”

“What it comes down to is I don’t think it really matters who the quarterback is,” Wright said. “If all 11 guys on offense don’t show up to play, the same outcome will come.”

tower becomes vikings’ domain Vikings defensive back Chris Cook jumped into a photo of teammates as they posed in front of a Vikings logo projection during a team outing to the Tower of London. Related photos, C7

Ponder is at a crossroads in his career. He’s 12-17 with a 59.2 completion percentage, 33 touchdowns and 30 interceptions as a starter. This year, with a surprisingly unstable line in front of him, he’s turned the ball over seven times while ranking 30th in passer rating (65.9).

His rib injury came at the 14:55 mark of the second quarter last Sunday. After making a nice throw to Wright for an 11-yard gain, Ponder was knocked down and landed on by Browns nose tackle Phil Taylor.

Ponder said he felt the pain, but never left the game, completing seven of his next nine passes in the first half but only 10 of 20 for 63 yards in the second half. Both of his rushing touchdowns also came after the rib injury.

Ponder had a CT scan done Monday.

“They wanted to make sure I didn’t have a bruised lung because they didn’t want me to fly [to London] with a bruised lung,” said Ponder, who practiced a little on Wednesday and more Thursday. “They weren’t thinking it was going to be a fracture, but it showed up. And it was fractured all the way through.”

Ponder is making $1.3 million this year and has a $1.76 million guarantee for 2014, the final year of his rookie contract. Cassel has what essentially is a one-year, $3.7 million deal. There’s $4 million on the table for him next year, but only if both sides agree to pick up the option.